Underwater housing with tilted camera mount for dual lens spherical camera

ABSTRACT

An underwater housing includes a mounting plate, a first dome attached to a first surface of the mounting plate, and a second dome attached to a second surface of the mounting plate in a back-to-back configuration. A camera mount for a dual-lens camera is oriented at a tilt angle relative to a plane of a mounting plate. The dual-lens camera has laterally offset back-to-back lenses. The tilt angle is set such that the optical axes of the dual-lens camera intersect the center points of the respective domes.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/426,084 filed on Nov. 23, 2016, the content of which is incorporatedby reference herein.

BACKGROUND Technical Field

This application relates generally to a camera housing and morespecifically to an underwater housing for a dual-lens camera.

Description of the Related Art

Operating a camera underwater may be desirable under a variety ofsituations. For non-waterproof cameras, a separate waterproof housingmay be used to prevent damage to the camera. A challenge with existingunderwater housings is that the housing may refract light passingthrough it, thereby distorting the images captured by the camera whenused within the housing. This effect is particularly problematic inmulti-lens camera systems in which the distortion may affect differentlenses differently, thereby making compensation for these effects moredifficult.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The disclosed embodiments have other advantages and features which willbe more readily apparent from the following detailed description of theinvention and the appended claims, when taken in conjunction with theaccompanying drawings, in which:

FIG. 1A is a first perspective view of an embodiment of a dual-lenscamera.

FIG. 1B is a second perspective view of an embodiment of a dual-lenscamera.

FIG. 2 is a top view of an embodiment of a dual-lens camera.

FIG. 3 is a top view of an embodiment of a dual-lens camera in anunderwater housing.

FIG. 4 is a front view of an embodiment of a mounting plate for anunderwater housing for a dual-lens camera.

FIG. 5 is a perspective and exploded view of an embodiment of anunderwater housing for a dual-lens camera.

FIG. 6 is a diagram modeling the effect on field of view when an imaginglens is placed in a simple dome.

FIG. 7 is a diagram modeling the effect on focus when an imaging lens isplaced in a simple dome.

FIG. 8 is a diagram modeling the effect on focus when an imaging lens isplaced in a dome modeled as a positive lens.

FIG. 9 is a block diagram illustrating an example embodiment of adual-lens camera.

DETAILED DESCRIPTION

The figures and the following description relate to preferredembodiments by way of illustration only. It should be noted that fromthe following discussion, alternative embodiments of the structures andmethods disclosed herein will be readily recognized as viablealternatives that may be employed without departing from the principlesof what is claimed.

Reference will now be made in detail to several embodiments, examples ofwhich are illustrated in the accompanying figures. It is noted thatwherever practicable similar or like reference numbers may be used inthe figures and may indicate similar or like functionality. The figuresdepict embodiments of the disclosed system (or method) for purposes ofillustration only. One skilled in the art will readily recognize fromthe following description that alternative embodiments of the structuresand methods illustrated herein may be employed without departing fromthe principles described herein.

Configuration Overview

An underwater camera system includes a dual-lens camera and anunderwater housing. A camera body comprises at least a first face and asecond face opposite the first face. A first image sensor captures firstimages corresponding to a first field of view. A second image sensorcaptures second images corresponding to a second field of view. A firstlens assembly focuses light entering the first lens assembly onto thefirst image sensor. A second lens assembly focuses light entering thesecond lens assembly onto the second image sensor. The first lensassembly has a first optical axis laterally offset from a second opticalaxis of the second lens assembly. The underwater housing comprises amounting plate having a perimeter portion surrounding a cutout. Theperimeter portion has a first plurality of attachment points on a firstsurface of the mounting plate and a second plurality of attachmentpoints on a second surface of the mounting plate opposite the firstsurface. A first dome is coupled to the first surface of the mountingplate via the first plurality of attachment points. A second dome iscoupled to the second surface of the mounting plate via the secondplurality of attachment points. A camera mount secures the dual-lenscamera within the cutout. The camera mount is structured to secure thecamera at a tilt angle offset from a plane of the mounting plate suchthat the first optical axis intersects a center point on a surface ofthe first dome and such that the second optical axis intersects a centerpoint of a surface of the second dome.

In another embodiment, an underwater housing houses a dual-lens camera.A mounting plate comprises a perimeter portion surrounding a cutout. Theperimeter portion has a first plurality of attachment points on a firstsurface of the mounting plate and a second plurality of attachmentpoints on a second surface of the mounting plate opposite the firstsurface. A first dome is coupled to the first surface of the mountingplate via the first plurality of attachment points. A second dome iscoupled to the second surface of the mounting plate via the secondplurality of attachment points. A camera mount secures the dual-lenscamera within the cutout. The camera mount is structured to secure thecamera at a tilt angle offset from a plane of the mounting plate suchthat the first optical axis intersects a center point on a surface ofthe first dome and such that the second optical axis intersects a centerpoint of a surface of the second dome.

In yet another embodiment, an underwater housing comprises a waterproofhousing and a camera mount. The waterproof housing has a first dome anda second dome with a waterproof seal in between them. The camera mountsecures within the waterproof housing, a camera having a first lensassembly with a first optical axis laterally offset from a second lensassembly with a second optical axis. The camera mount is structured tosecure the camera at a tilt angle offset from a plane of the mountingplate such that the first optical axis intersects a center point on asurface of the first dome and such that the second optical axisintersects a center point of a surface of the second dome.

Dual-Lens Camera

FIGS. 1A-1B are perspective views illustrating an example embodiment ofa dual-lens camera 100. In an embodiment, the camera 100 captures aspherical or near-spherical field of view. For example, in oneembodiment, the camera 100 comprises two lens assemblies 112, 114 onopposite faces of the camera body 102. The lens assemblies 112, 114 mayeach capture a hemispherical or hyper-hemispherical field of view thatcan be stitched together to generate spherical images. In an embodiment,the lens assemblies 112, 114 are laterally offset from each such thattheir respective optical axes 122, 124, are separated by a lateraldistance d and are anti-parallel to each other (e.g., receive light fromopposite directions).

FIG. 2 is a top cross-sectional view of the camera showing the offsetconfiguration of the lens assemblies 112, 114 and respective opticalaxes 122, 124. The lens assemblies 112, 114 each have respectivehyper-hemispherical fields of view 200-a, 200-b.

Underwater Housing Structure

FIG. 3 illustrates a top cross-sectional view of an underwater housing300 for housing a dual-lens camera 100. The housing 300 comprises acenter mounting plate 340, a first dome 332, and a second dome 334. Themounting plate 340 may comprise a rigid material (e.g., machinedaluminum or hard plastic) and may have a cutout in which the camera 100may be mounted. The first dome 332 and second dome 334 may each comprisea transparent waterproof material (e.g., plastic) shaped as ahemisphere, a quasi-hemisphere, a raised hemisphere comprising ahemispherical portion and a cylindrical portion, a shortened hemispherecomprising a less than 180 degree portion of a circular arc, a parabolicdome, or other convex or lens shape. The first dome 332 may comprise aflange portion 342 around an edge of the dome 332 (thus, forming a ring)that extends radially from the dome 332 and may be structured such thata flat surface of the flange portion 342 mates with a first surface ofthe mounting plate 340. Similarly, the second dome 334 may comprise aflange portion 344 around an edge of the dome 334 (thus forming a ring)that extends radially from the dome 334 and may be structured such thata flat surface of the flange portion 344 mates with a second surface ofthe mounting plate 340. The flange portions 342, 344 may be fastened tothe mounting plate 340 by a fastener such as a screw, nut and bolt,clip, or other fastener. In an embodiment, the domes 132, 134 arecoupled to the mounting plate 140 in a back-to-back configuration withtheir respective edges aligned to form a substantially sphericalstructure.

A camera mount secures the camera 100 at a tilt angle relative to aplane of the mounting plate 340. Thus, the optical axes 122, 124 of thelens assemblies 112, 114 are off-perpendicular from the plane of themounting plate 340. In an embodiment, the tilt angle is set such thatthe optical axis 122 of the first lens assembly 112 intersects a centerpoint (e.g., a zenith point) on a surface of the first dome 332 and theoptical axis 124 of the second lens assembly 114 intersects a centerpoint (e.g., a zenith point) on a surface of the second dome 334. Forexample, in one embodiment, a tilt angle is given as:

${{Tilt}\mspace{14mu} {Angle}} = {{\frac{1}{2}\sin^{- 1}\frac{d}{R}} - {\sin^{- 1}\frac{d}{nR}}}$

where d is the lateral distance between the centers of the lensassemblies 112, 114 (also corresponding to the lateral distance betweenthe respective optical axes 122, 124), R is radius of the domes 332,334, and n is the index of refraction of the external environment (e.g.,outside the domes 332, 334) to the internal environment (e.g., insidethe domes 332, 334).

The tilted mount configuration beneficially improves optical performanceof the dual-lens camera 100 because the distortion introduced by thedomes 132, 134 (which act as a lens) can be minimized when the opticalaxis of the lens assemblies 112, 114 aligns with the center of therespective domes 132, 134. Furthermore, any distortion introduced by thedomes 132, 134 will be approximately equal for each of the lensassemblies 112, 114, thus reducing complexity. Furthermore, even withoutany compensation, the hemispheres may be stitched together withoutasymmetric distortion affecting the stitching algorithm.

FIG. 4 illustrates a front view of an example embodiment of the mountingplate 340. The mounting plate 340 includes a cutout 404 in which thecamera 100 is mounted via a mounting structure 402. In an embodiment,the mounting plate 340 comprises a ring structure. In an embodiment,fastening locations 442 are provided on the mounting plate 340 thatenable a dome 132 to be coupled to the mounting plate 340. The mountingstructure 402 may be oriented at a fixed angle relative to the plane ofthe mounting plate 340 or may comprise a swivel-mount that enables thetilt angle to be adjusted manually.

FIG. 5 illustrates a front view 522 and an exploded perspective view 524of an example embodiment of an underwater housing 300 for housing adual-lens spherical camera 100. As illustrated in the exploded view 524,a sealing element 502 such as a silicone rubber O-ring may be placedbetween the dome 332 and the mounting plate 340 and between the dome 334and the mounting plate 340 to provide a watertight seal between thedomes 332, 334 and the plate 340. The embodiment of FIG. 5 alsoillustrates a particular embodiment of a camera mount 402 for mountingthe camera 100 to the plate 340. In this example, a three finger mount402 on the housing 300 may be interlocked with a reciprocal two fingermount (not shown) on the camera 100 and the camera 100 may be secured tothe housing via a screw (not shown) that passes through aligned holes onthe two finger of the camera 100 three finger mount 402 of the housing300. The mount may be set at a fixed angle relative to the plane of themounting plate 340 or may comprise an adjustable-angle mount. In anembodiment, additional two finger mounts 504, 506 may be located on anouter edge of the plate 340 and may provide attachment points forvarious external accessories.

Analysis of Dome Effects

The domes 332, 334 may affect the respective fields of view of thecorresponding lens assemblies 112, 114. As illustrated in FIG. 6, a mainimaging lens 602 has a start point is an axial distance h within a dome604 relative to the start point of the dome 604 which is aligned withthe optical axis of the lens 602. The main imaging lens 602 has a focallength f and the dome has a radius R. The dome 604 is filled with air(n≈1). Outside of the dome 604, the refractive index is n (n≈1.33underwater). ϕ is the imaging ray angle in air and ϕ′ is the imaging rayangle outside of the dome 604. Finally, there are internal angles α, βand γ and external angles δ and ε. Herein, the relationship between αand δ is to be found using Snell's law.

The law of sines provides the following:

$\begin{matrix}{\frac{R}{\sin \; \gamma} = {\frac{h}{\sin \; \alpha} = \frac{\rho}{\sin \; \beta}}} & (1)\end{matrix}$

As a result,

$\begin{matrix}{{\sin \; \alpha} = {\frac{{h \cdot \sin}\; \gamma}{R} = {\frac{h \cdot {\sin ( {180 - \varphi} )}}{R} = {{\frac{{h \cdot \sin}\; \varphi}{R}->\alpha} = {\sin^{- 1}( \frac{{h \cdot \sin}\; \varphi}{R} )}}}}} & (2)\end{matrix}$

where R<0 in this geometry to obey optical definitions to follow. Then,using Snell's law,

$\begin{matrix}{{{{1 \cdot \sin}\; \alpha} = n}{ {{\cdot \sin}\; \delta}arrow\delta  = {\sin^{- 1}( \frac{{h \cdot \sin}\; \varphi}{{R} \cdot n} )}}} & (3)\end{matrix}$

As well, it is easy to see that

$\begin{matrix}{ɛ = {\delta - \alpha}} & (4) \\{and} & \; \\{\varphi^{\prime} = {{\varphi + ɛ} = {\varphi + {\sin^{- 1}( \frac{{h \cdot \sin}\; \varphi}{{R} \cdot n} )} - {\sin^{- 1}( \frac{{h \cdot \sin}\; \varphi}{R} )}}}} & (5)\end{matrix}$

Therefore, Equations 5 and 4 can be used to calculate the new ray anglein water, ϕ′, or the field of view change, ε, respectively, as afunction of ϕ.

If the optical axis of the lens 602 is offset from the optical axis ofthe dome 604, then there will be polar angle dependent refractiveeffects similar in nature to but orthogonal to those of ε. Thus,different offsets will change the field of view differently. By usingthe offset dome configuration described above, these effects can beavoided and any field of view change will occur equally for each lens.This greatly simplifies the stitching algorithm.

The focus quality may also change when the camera and dome system isplaced under water. There are two effects herein that will alter wherethe image plane lands relative to a sensor plane (e.g., the focusshift), 1) the curvature of the dome induces a negative optical powerwhen inserted underwater thereby increasing the desired image distance(U) and 2) the change in optical path length of the portion of theobject distance that is in the water will induce an optical reduction inthe overall object distance (though there is no change in the physicalobject distance) thereby increasing desired mage distance. The geometryfor this is diagrammed in FIG. 7.

In FIG. 7, the main parameters are the same as those described in FIG.6. The additional parameters are the object distance, V (the physicaldistance as measured from the start point of the lens 602 to theobject), the image distance, U, the input ray's height above the opticalaxis, r, the input ray's propagation angle relative to the optical axis,θ, the output ray's height above the optical axis, r′ and the outputray's propagation angle relative to the optical axis, θ′. The imagingsystem in FIG. 7 may be analyzed under the paraxial approximation usingthe ABCD matrix mathematics. After analyzing the system, the differencein the image distance when the in-dome system is in air versus the imagedistance when it is in water may be calculated. This gives the defocusdistance which is desirable for determining how system design choicesimpact image quality.

The ABCD matrix multiplication equation for the optical system shown inFIG. 7 is given below, noting that this formalism works whetherexamining the system forwards or backwards.

$\begin{matrix}{\begin{pmatrix}r^{\prime} \\\theta^{\prime}\end{pmatrix} = {\begin{pmatrix}1 & \lbrack {V - p} \rbrack \\0 & 1\end{pmatrix}\begin{pmatrix}1 & 0 \\\Gamma & \frac{1}{n}\end{pmatrix}\begin{pmatrix}1 & \rho \\0 & 1\end{pmatrix}\begin{pmatrix}1 & 0 \\\frac{- 1}{f} & 1\end{pmatrix}\begin{pmatrix}1 & U \\0 & 1\end{pmatrix}\begin{pmatrix}r \\\theta\end{pmatrix}}} & (6)\end{matrix}$

Herein,

$\begin{matrix}{\Gamma = \frac{1 - n}{R \cdot n}} & (7)\end{matrix}$

In this geometry R<0 but U, V, ρ, h and n are all positive. In theformalization of the ABCD law for analyzing optical systems, all of the2×2 optical element matrices can be multiplied into a single 2×2 matrixfor the system. When this is done, the general form of Equation 6becomes

$\begin{matrix}{\begin{pmatrix}r^{\prime} \\\theta^{\prime}\end{pmatrix} = {\begin{pmatrix}A & B \\C & D\end{pmatrix}\begin{pmatrix}r \\\theta\end{pmatrix}}} & (8)\end{matrix}$

Expansion of Equation 8 then reveals

r′=r·A+θ·B  (9a)

θ′=r·C+θ·D  (9b)

It may be determined by how much the image distance, U, shifts when thedome is in water relative to when it is in air. One technique is totrack how U changes to keep the system in focus. If the input ray heightis zero at the image plane (i.e., if the ray is on the optical axis atthe image plane) then at focus the output ray height will also be zeroat the object plane, and this will be true for all ray angles, θ.Examining Equation 9a, it can be seen that this condition is met if andonly if the term B is equal to zero (at focus for r=0, r′=0 and0=anything, so B=0 is required). Under this constraint it can be shown,

$\begin{matrix}{U = \frac{( {\rho + \frac{( {V - \rho} )}{n} + {\rho \cdot ( {V - \rho} ) \cdot ( \frac{1 - n}{R \cdot n} )}} ) \cdot f}{\begin{matrix}{\rho + \frac{( {V - \rho} )}{n} + {\rho \cdot ( {V - \rho} ) \cdot ( \frac{1 - n}{R \cdot n} )} -} \\{ {( {1 + {( {V - \rho} ) \cdot ( \frac{1 - n}{R \cdot n} )}} ) \cdot f}}\end{matrix}}} & (10)\end{matrix}$

Equation 10 can be used to apply two specific imaging conditions toobtain two specific values for U (i.e., one for when the dome is inliquid with n=n and the other for when the dome is in air with n=1).Then, simply calculating the difference between these two values for Uwill reveal the focus shift that occurs (i.e., from perfect focus in airto slightly out of focus in liquid). This is given as,

$\begin{matrix}{{\Delta \; U} = {\frac{( {\rho + \frac{( {V - \rho} )}{n} + {\rho \cdot ( {V - \rho} ) \cdot ( \frac{1 - n}{R \cdot n} )}} ) \cdot f}{\begin{matrix}{\rho + \frac{( {V - \rho} )}{n} + {\rho \cdot ( {V - \rho} ) \cdot ( \frac{1 - n}{R \cdot n} )} -} \\{ {( {1 + {( {V - \rho} ) \cdot ( \frac{1 - n}{R \cdot n} )}} ) \cdot f}}\end{matrix}} - \frac{V \cdot f}{V \cdot f}}} & (11)\end{matrix}$

Using the equation above, the dome may be customized to manage tradeoffsunder various scenarios. Furthermore, any loss of focus can bequantified and compensated for in post-processing.

In addition to loss of field of view and a shift in the focal plane,taking a dome of air under water will cause a displacement of water.This principle can be applied to calculate the weight to be added to thesystem to make it neutrally buoyant under water. The mass of displacedwater is calculated as:

M=D·V  (12)

where M is the mass of the displaced water, D is the density of water (1gm/cc) and V is the volume of displaced water. The volume of displacedwater is given through simple geometry as

V=4/3·π·|R| ³  (13)

Next the weight of the camera and dome itself, m, is subtracted from Mto achieve the final value for how much more weight can be added to thesystem to make it neutrally buoyant under water, B. This is given as

$\begin{matrix}{B = {{M - m} = {\frac{4 \cdot \pi \cdot {R}^{3} \cdot D}{3} - m}}} & (14)\end{matrix}$

As an example, if R=−75 mm and m=0.8 kg then B≈1 kg. If R grows to −100mm, then B grows to 3.4 kg for the same camera mass. This substantialgrowth in B (approximately 3.4 kg of buoyancy weight at R=−100 mm versusapproximately 1 kg of buoyancy weight at R=−75 mm) comes with a somewhatbetter focus (approximately 8 um of defocus at R=−100 mm versusapproximately 11 um of defocus at R=−75 mm) and a slightly lower FOVdegradation (approximately 2.15 degrees of FOV loss at R=−100 mm versusapproximately 2.9 degrees FOV loss at R=−75 mm). As can be seen from theexamples above, the tradeoffs between field of view loss, focus, andbuoyancy may be managed depending on the desired application.

The effects of the simple dome cover model described above may be evenbetter approximated by instead modeling the dome as a positive lens. Inthis manner, by varying the power of this lens focus may be traded offwith the dome in the water and/or in air and the lens dome's effect onfield of view. As well, by adding glass weight to the dome by allowingit to thicken into a positive lens, the underwater buoyancy can also beimproved.

FIG. 8 diagrams the geometry to analyze the ABCD matrix mathematics forthis system. In this system, the dome 802 is modeled as having an outerdome surface of radius, R1 and an inner dome surface of radius, R2.Using the parameters in FIG. 8, the ABCD system of equations becomes

$\begin{matrix}{\begin{pmatrix}r^{\prime} \\\theta^{\prime}\end{pmatrix} = {\begin{pmatrix}1 & b \\0 & 1\end{pmatrix}\begin{pmatrix}\alpha & \beta \\\chi & \delta\end{pmatrix}\begin{pmatrix}1 & \rho \\0 & 1\end{pmatrix}\begin{pmatrix}1 & 0 \\\frac{- 1}{f} & 1\end{pmatrix}\begin{pmatrix}1 & U \\0 & 1\end{pmatrix}\begin{pmatrix}r \\\theta\end{pmatrix}}} & (15)\end{matrix}$

In Equation 15, the terms α, β, χ, δ come from the ABCD matrix for athick lens, given as

$\begin{matrix}{\begin{pmatrix}\alpha & \beta \\\chi & \delta\end{pmatrix} = {\begin{pmatrix}1 & 0 \\\frac{n_{2} - n_{3}}{R_{2} \cdot n_{3}} & \frac{n_{2}}{n_{3}}\end{pmatrix}\begin{pmatrix}1 & t \\0 & 1\end{pmatrix}\begin{pmatrix}1 & 0 \\\frac{n_{1} - n_{2}}{R_{1} \cdot n_{2}} & \frac{n_{1}}{n_{2}}\end{pmatrix}}} & (16)\end{matrix}$

Doing the math on Equation 16 then gives

$\begin{matrix}{\alpha = {1 + {t \cdot ( \frac{n_{1} - n_{2}}{R_{1} \cdot n_{2}} )}}} & ( {17a} ) \\{\beta = {t \cdot ( \frac{n_{1}}{n_{2}} )}} & ( {17b} ) \\{\chi = {( \frac{n_{2} - n_{3}}{R_{2} \cdot n_{3}} ) + {t \cdot ( \frac{n_{1} - n_{2}}{R_{1} \cdot n_{2}} ) \cdot ( \frac{n_{2} - n_{3}}{R_{2} \cdot n_{3}} )} + {( \frac{n_{2}}{n_{3}} ) \cdot ( \frac{n_{1} - n_{2}}{R_{1} \cdot n_{2}} )}}} & ( {17c} ) \\{\delta = {{t \cdot ( \frac{n_{2} - n_{3}}{R_{2} \cdot n_{3}} ) \cdot ( \frac{n_{1}}{n_{2}} )} + ( \frac{n_{1}}{n_{3}} )}} & ( {17d} )\end{matrix}$

Solving Equation 15 for the focus condition (the B term is set to zero),the equation for U can be determined as

$\begin{matrix}{U = \frac{( {{\rho \cdot \alpha} + \beta + {\rho \cdot \chi \cdot b} + {\delta \cdot b}} ) \cdot f}{( {{\rho \cdot \alpha} + \beta + {\rho \cdot \chi \cdot b} + {\delta \cdot b}} ) - {( {\alpha + {\chi \cdot b}} ) \cdot f}}} & (18)\end{matrix}$

In one example embodiment, it can be seen that when R2=−75 mm andR1=−175 mm, the net focus shift is zero microns, meaning that the systemstays in focus when in the lens dome and underwater relative to when itis not in the dome and in air. Similarly, when R2=−100 mm and R1=−250mm, the net focus shift is also zero microns. Under either of these twoconditions, the system goes out of focus if it is pulled out of thewater but left in the dome. For example, when R2=−75 mm and R1=−175 mm,the net focus shift is −22.5 microns in air. Also, when R2=−100 mm andR1=−250 mm, the net focus shift is −17 microns in air. In anotherembodiment, a compromise may be made such that there is a small netfocus shift in both air and under water. For example, when R2=−75 mm andR1=−92 mm, the net focus shift is +9.2 um in water and −9.2 um in air,while when R2=−100 mm and R1=−125 mm, the net focus shift is +6.8 um inwater and −6.8 um in air.

Example Camera Configuration

FIG. 9 is a block diagram illustrating a camera 100, according to oneembodiment. In the illustrated embodiment, the camera 100 may comprisetwo camera cores 910 (e.g., camera core A 910-A and camera core B 910-B)each comprising a hemispherical lens 912 (e.g., hemispherical lens 912-Aand hemispherical lens 912-B), an image sensor 914 (e.g., image sensor914-A and image sensor 914-B), and an image processor 916 (e.g., imageprocessor 916-A and image processor 916-B). The camera 100 mayadditionally include a system controller 920 (e.g., a microcontroller ormicroprocessor) that controls the operation and functionality of thecamera 100 and system memory 930 that may be configured to storeexecutable computer instructions that, when executed by the systemcontroller 920 and/or the image processors 916, perform the camerafunctionalities described herein.

An input/output (I/O) interface 960 may transmit and receive data fromvarious external devices. For example, the I/O interface 960 mayfacilitate the receiving or transmitting video or audio informationthrough an I/O port. Examples of I/O ports or interfaces may include USBports, HDMI ports, Ethernet ports, audioports, and the like.Furthermore, embodiments of the I/O interface 960 may include wirelessports that can accommodate wireless connections. Examples of wirelessports may include Bluetooth, Wireless USB, Near Field Communication(NFC), and the like. The I/O interface 960 may also include an interfaceto synchronize the camera 100 with other cameras or with other externaldevices.

A control/display subsystem 970 may include various control and displaycomponents associated with operation of the camera 100 including, forexample, LED lights, a display, buttons, microphones, speakers, and thelike. The audio subsystem 950 may include, for example, one or moremicrophones and one or more audio processors to capture and processaudio data correlated with video capture.

Sensors 940 may capture various metadata concurrently with, orseparately from, video capture. For example, the sensors 940 may capturetime-stamped location information based on a global positioning system(GPS) sensor, and/or an altimeter. Other sensors 940 may be used todetect and capture orientation of the camera 100 including, for example,an orientation sensor, an accelerometer, a gyroscope, or a magnetometer.

In alternative embodiments, one or more components of the camera cores910 may be shared between different camera cores 910. For example, inone embodiment, the camera cores 910 may share one or more imageprocessors 916. Furthermore, in alternative embodiments, the cameracores 910 may have additional separate components such as, for example,dedicated system memory 930 or system controllers 920.

In one embodiment, the camera 100 may comprise a twinhyper-hemispherical lens system that capture two image hemispheres withsynchronized image sensors which combine to form a contiguous sphericalimage. Each of the two streams generated by camera cores 910 may beseparately encoded and then aggregated in post processing to form thespherical video. For example, each of the two streams may be encoded at2880×2880 pixels at 30 frames per second and combined to generate a5760×2880 spherical video at 30 frames per second. Other resolutions andframe rates may also be used.

In an embodiment the spherical content may be captured at a high enoughresolution to guarantee the desired output from the relevant sub-framewill be of sufficient resolution. For example, if a horizontal field ofview of 120° at an output resolution of 1920×1080 pixels is desired inthe final output video, the original spherical capture may include ahorizontal 360° resolution of at least 5760 pixels (3×1920).

Additional Configuration Considerations

Throughout this specification, some embodiments have used the expression“coupled” along with its derivatives. The term “coupled” as used hereinis not necessarily limited to two or more elements being in directphysical or electrical contact. Rather, the term “coupled” may alsoencompass two or more elements are not in direct contact with eachother, but yet still co-operate or interact with each other.

Likewise, as used herein, the terms “comprises,” “comprising,”“includes,” “including,” “has,” “having” or any other variation thereof,are intended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus.

In addition, use of the “a” or “an” are employed to describe elementsand components of the embodiments herein. This is done merely forconvenience and to give a general sense of the invention. Thisdescription should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

Finally, as used herein any reference to “one embodiment” or “anembodiment” means that a particular element, feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. The appearances of the phrase “in oneembodiment” in various places in the specification are not necessarilyall referring to the same embodiment.

Upon reading this disclosure, those of skill in the art will appreciatestill additional alternative structural and functional designs asdisclosed from the principles herein. Thus, while particular embodimentsand applications have been illustrated and described, it is to beunderstood that the disclosed embodiments are not limited to the preciseconstruction and components disclosed herein. Various modifications,changes and variations, which will be apparent to those skilled in theart, may be made in the arrangement, operation and details of the methodand apparatus disclosed herein without departing from the spirit andscope defined in the appended claims.

1. An underwater camera system, comprising: a dual-lens cameracomprising: a camera body comprising at least a first face and a secondface opposite the first face; a first image sensor to capture firstimages corresponding to a first field of view; a second image sensor tocapture second images corresponding to a second field of view; a firstlens assembly to focus light entering the first lens assembly onto thefirst image sensor; a second lens assembly to focus light entering thesecond lens assembly onto the second image sensor, wherein the firstlens assembly has a first optical axis laterally offset from a secondoptical axis of the second lens assembly; an underwater housingcomprising: a mounting plate comprising a perimeter portion surroundinga cutout, the perimeter portion having a first plurality of attachmentpoints on a first surface of the mounting plate and a second pluralityof attachment points on a second surface of the mounting plate oppositethe first surface; a first dome coupled to the first surface of themounting plate via the first plurality of attachment points; a seconddome coupled to the second surface of the mounting plate via the secondplurality of attachment points; and a camera mount for securing thedual-lens camera within the cutout, the camera mount structured tosecure the camera at a tilt angle offset from a plane of the mountingplate such that the first optical axis intersects a center point on asurface of the first dome and such that the second optical axisintersects a center point of a surface of the second dome.
 2. Theunderwater camera system of claim 1, wherein the first dome comprises afirst transparent substantially hemispherical portion and a first flangeportion, the first flange portion extending radially from a firstsubstantially circular edge of the first hemisphere portion, the firstflange portion having a first surface that mates with the first surfaceof the mounting plate and is secured with the mounting plate via thefirst plurality of attachment points; and the second dome comprises asecond transparent substantially hemispherical portion and a secondflange portion, the second flange portion extending radially from asecond substantially circular edge of the second hemisphere portion, thesecond flange portion having a second surface that mates with acorresponding surface of the second surface of the mounting plate and issecured with the mounting plate via the second plurality of attachmentpoints.
 3. The underwater camera system of claim 2, wherein theunderwater housing further comprises: a first compressible sealingelement between the first flange portion and the first surface of themounting plate; and a second compressible sealing element between thesecond flange portion and the second surface of the mounting plate. 4.The underwater camera system of claim 1, wherein the tilt angle relativeto the plane of the mounting plate is given by${\frac{1}{2}\sin^{- 1}\frac{d}{R}} - {\sin^{- 1}\frac{d}{nR}}$ whered is a lateral distance between the first lens assembly and the secondlens assembly, R is a radius of the first dome and the second dome, andn is an index of refraction of an external environment outside the firstdome and the second dome to an internal environment inside the firstdome and the second dome.
 5. The underwater camera system of claim 1,wherein the first dome and the second dome each comprise a hemisphere.6. The underwater camera system of claim 1, wherein the first dome andthe second dome each comprise a raised hemisphere comprising ahemispherical portion and a cylindrical portion.
 7. The underwatercamera system of claim 1, wherein the first dome and the second domeeach comprise a parabolic surface.
 8. An underwater housing for adual-lens camera, comprising: a mounting plate comprising a perimeterportion surrounding a cutout, the perimeter portion having a firstplurality of attachment points on a first surface of the mounting plateand a second plurality of attachment points on a second surface of themounting plate opposite the first surface; a first dome coupled to thefirst surface of the mounting plate via the first plurality ofattachment points; a second dome coupled to the second surface of themounting plate via the second plurality of attachment points; and acamera mount for securing the dual-lens camera within the cutout, thedual-lens camera having a first lens assembly with a first optical axislaterally offset from a second lens assembly with a second optical axis,the camera mount structured to secure the camera at a tilt angle offsetfrom a plane of the mounting plate such that the first optical axisintersects a center point on a surface of the first dome and such thatthe second optical axis intersects a center point of a surface of thesecond dome.
 9. The underwater camera system of claim 8, wherein thefirst dome comprises a first transparent substantially hemisphericalportion and a first flange portion, the first flange portion extendingradially from a first substantially circular edge of the firsthemisphere portion, the first flange portion having a first surface thatmates with the first surface of the mounting plate and is secured withthe mounting plate via the first plurality of attachment points; and thesecond dome comprises a second transparent substantially hemisphericalportion and a second flange portion, the second flange portion extendingradially from a second substantially circular edge of the secondhemisphere portion, the second flange portion having a second surfacethat mates with a corresponding surface of the second surface of themounting plate and is secured with the mounting plate via the secondplurality of attachment points.
 10. The underwater camera system ofclaim 9, wherein the underwater housing further comprises: a firstcompressible sealing element between the first flange portion and thefirst surface of the mounting plate; and a second compressible sealingelement between the second flange portion and the second surface of themounting plate.
 11. The underwater camera system of claim 8, wherein thetilt angle relative to the plane of the mounting plate is given by${\frac{1}{2}\sin^{- 1}\frac{d}{R}} - {\sin^{- 1}\frac{d}{nR}}$ whered is a lateral distance between the first lens assembly and the secondlens assembly, R is a radius of the first dome and the second dome, andn is an index of refraction of an external environment outside the firstdome and the second dome to an internal environment inside the firstdome and the second dome.
 12. The underwater camera system of claim 8,wherein the first dome and the second dome each comprise a hemisphere.13. The underwater camera system of claim 8, wherein the first dome andthe second dome each comprise a raised hemisphere comprising ahemispherical portion and a cylindrical portion.
 14. The underwatercamera system of claim 8, wherein the first dome and the second domeeach comprise a parabolic surface.
 15. An underwater housing for adual-lens camera, comprising: a waterproof housing having a first domeand a second dome with a waterproof seal in between them; and a cameramount for securing within the waterproof housing, a camera having afirst lens assembly with a first optical axis laterally offset from asecond lens assembly with a second optical axis, the camera mountstructured to secure the camera at a tilt angle offset from a plane ofthe mounting plate such that the first optical axis intersects a centerpoint on a surface of the first dome and such that the second opticalaxis intersects a center point of a surface of the second dome.
 16. Theunderwater camera system of claim 15, wherein the first dome comprises afirst transparent substantially hemispherical portion and a first flangeportion, the first flange portion extending radially from a firstsubstantially circular edge of the first hemisphere portion, the firstflange portion having a first surface that mates with the first surfaceof the mounting plate and is secured with the mounting plate via thefirst plurality of attachment points; and the second dome comprises asecond transparent substantially hemispherical portion and a secondflange portion, the second flange portion extending radially from asecond substantially circular edge of the second hemisphere portion, thesecond flange portion having a second surface that mates with acorresponding surface of the second surface of the mounting plate and issecured with the mounting plate via the second plurality of attachmentpoints.
 17. The underwater camera system of claim 16, wherein theunderwater housing further comprises: a first compressible sealingelement between the first flange portion and the first surface of themounting plate; and a second compressible sealing element between thesecond flange portion and the second surface of the mounting plate. 18.The underwater camera system of claim 15, wherein the tilt anglerelative to the plane of the mounting plate is given by${\frac{1}{2}\sin^{- 1}\frac{d}{R}} - {\sin^{- 1}\frac{d}{nR}}$ whered is a lateral distance between the first lens assembly and the secondlens assembly, R is a radius of the first dome and the second dome, andn is an index of refraction of an external environment outside the firstdome and the second dome to an internal environment inside the firstdome and the second dome.
 19. The underwater camera system of claim 15,wherein the first dome and the second dome each comprise a raisedhemisphere comprising a hemispherical portion and a cylindrical portion.20. The underwater camera system of claim 15, wherein the first dome andthe second dome each comprise a parabolic surface.